Python: How to attach policy to AWS IoT thing?

Question

I wrote Python script to create AWS IoT thing and policy. I attach policy to the IoT thing with the code as follows.

iot_client.attach_policy(policyName=policy_name, target=thing_arn)

I got the errors as follows:

create-iot-device.py", line 36, in iot_client.attach_policy(policyName=policy_name, target=thing_arn)

botocore.errorfactory.InvalidRequestException: An error occurred (InvalidRequestException) when calling the AttachPolicy operation: Invalid Target: arn:aws:iot:us-east-1:428999999999:thing/YourIoTThingName

The following is the related code.

import boto3
import os
from OpenSSL import crypto

# AWS IoT settings
iot_client = boto3.client('iot')
iot_thing_name = 'YourIoTThingName'
policy_name = 'YourPolicyName'

# Create IoT thing
response = iot_client.create_thing(thingName=iot_thing_name)
thing_arn = response['thingArn']

policy_document = '''
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": "iot:*",
      "Resource": "*"
    }
  ]
}
'''

# Remove leading spaces from policy_document
policy_document = policy_document.strip()

response = iot_client.create_policy(policyName=policy_name, policyDocument=str(policy_document))

# Attach policy to thing
iot_client.attach_policy(policyName=policy_name, target=thing_arn)

Answer 1

You cannot attach an IoT policy to a thing, you attach it to a certificate. The certificate is then attached to a thing.

You can find in the documentation how to do it: https://docs.aws.amazon.com/iot/latest/developerguide/attach-to-cert.html